Craft Your Own Animatronic Kitty Ears [Instructables How-To]

Emily Dubovoy — Sep 26 2012

I have a confession… there was a pretty serious anime phase I went through that lasted from kindergarten up until… well, okay… I still love anime. Between the plots, epic battle scenes, and sick graphics, there were many hours dwindled away in my bedroom lost to “Naruto,” “Rurouni Kenshin,” and “Lovely Complex.” I think what really got me hooked to anime (besides my awkward middle school anti-social tendencies) were the over-exaggerated emotions that every character seemed to have. If someone was embarrassed or unamused, suddenly a huge sweat drop would drip from their foreheads. Or when someone was excited, sprouting cat ears was the only accurate way to depict such a feeling.

Our post yesterday on Neurowear’s latest animal accessories reminded us of their cat ears called Necomimi that can give us the ability that I’ve always dreamed of. People can now read your mood before you even say a word. Just imagine all of the unwanted interactions that could be avoided if people could have a way to see that you are super ticked off >:(, hungry :0, or in love <3.

This button-operated headband can give you the appearance of being really excited and really adorable. Grab a couple of servo motors, some craft supplies, set aside a few hours, and in no time you could become internet cat famous. So let’s get down to business:

Once you have gathered your little goody basket of tools and materials, it’s time to pick out where your ears will go and firmly fasten them. Take your plastic headband and the arms that should have come with the servos you ordered. Figure out where you want them to go and drill, baby drill. Drill out three holes for each ear, six in total (three on the left and three on the right). The holes will be where you fasten the servo arms later on to control the left/right twisting movement of your little furry ear. Make sure they’re perpendicular to your face. Once you’re done drilling, screw in the servo arms. If any of screws jut up from the bottom and interfere with the motion of the servo, use your trusty dremel to shave off the top portion of the screw.

Next, attach the servo arms to metal brackets and glue them to the base servos you just attached to the headband. Once you’ve drilled the holes in the metal bracket, it’s time to glue them to the base servos with Gorilla glue. Use clothesline clips to keep the metal brackets attached to the base servos when they’re drying.

Draw out your kitty ears on a piece of paper, trace them onto the acrylic sheet twice, and then cut them out. Place the top servos on top of an ear cutout so they are as far down as possible without jutting out from the bottom.

And now for the techy part: wiring the circuit. A more detailed diagram of the circuit map can be found here.

After that’s all pieced together, download the hex file for the kitty ears project from GitHub and use AVRDUDE (or whatever other program you like) to program the ATTiny13. The ihex file can be found here. Then, go through each servo connection with the motor. It should be responsive to your commands.

Once your ears are working, calibrate the servos controlling them. After everything’s connected, power on the circuit by attaching the battery to the regulator and the regulator to the circuit. While the circuit is on, position each of the servos so that they rest in the desired home position.

Run through each of the preset motions to make sure the ears can move with the full range of motion without hitting the headband. This is when you can figure out any kinks and debug any potential problems.

The preset motions are as follows:· Press and hold – “Surprise”· Tap then press and hold – “Angry/Sad”· Tap three times – “Ear wink”

It’s smooth sailing after that. Cut. Sew. Stuff. Glue, and your ears should be looking a little more cute and cuddly.

Hang in there! All that’s left is to attach the circuit to the top of the headband, wrap the headband in some fur to cover up the circuitry, and put the wire in some housing.